Fig. 2From: High hemoglobin is associated with increased in-hospital death in patients with chronic obstructive pulmonary disease and chronic kidney disease: a retrospective multicenter population-based studyHb distribution based on CKD stratification. a, Compared with the non-CKD group, the CKD group showed a left-shifted Hb distribution curve. b, Compared with the early CKD group, the advanced group showed a noticeable left-shifted distribution curve. c, The CKD group had lower Hb levels than the non-CKD group. d, The advanced CKD group had lower Hb levels than the early CKD group. The dashed lines in panels A and B indicate the median Hb levels of each subgroup. * P < 0.001Back to article page